The aim of the study is to test whether a resource-sparing 4-week, 20-fraction course of accelerated hypofractionated radiotherapy is non-inferior to accelerated radiotherapy delivering 33 fractions over 5.5 weeks in the treatment of patients with Stage I-IV squamous cell carcinoma of the pharynx, larynx and oral cavity with the exception of paranasal sinus, nasopharyngeal and stage I-II glottic carcinomas.